The 2008 American primaries demonstrate the impact of the electoral system on the results. Statistical analysis of voting data assess the proportionality used in each of the parties’ electoral formulas, and its impact on the outcomes. The Democratic Party uses more proportional formulas than the Republican Party. In the Democratic Party, the proportional representation formulas had a direct mechanic influence in determining the party nominee. This in contrast to the Republican Party, where it seems that voter behavior changed due to the electoral formulas.

Working Papers

Duvergerian Effects: How the electoral system influences mass polarization (R&R at JoP)How do citizens react to permissive electoral systems and to the party fragmentation and polarization that follow? This paper examines mass polarization in a comparative perspective. By linking insights from two separate literatures, and examining cross-national data from 23 developed democracies, I show that permissive electoral systems produce a more polarized party system, and that this polarized political elite produces a more polarized public. I use the electoral system as an instrument for the party system polarization to estimate its effect on mass polarization, and take advantage of New Zealand's significant electoral reform to show mass polarization follows the rule change and party system polarization. Furthermore, using the data from New Zealand I show that the mass polarization that follows permissive electoral systems is a result of a change in the perception of the left-right range, rather than a result of a change in actual policy preferences.​

Bypassing Parliament: Why proportional elections produce majoritarian resultsAlthough voting behavior is expected to vary between electoral systems, results from elections held under proportional systems curiously present majoritarian patterns. Voters under proportional systems are not divided between different parties as much as could have been expected. Rather, voters swarm from wide ideological ranges and choose few, often moderate, parties. To explain these patterns, I propose an institutionally-dependent behavioral theory in which voters choose the party that maximizes the ideological compatibility with the post-election prime-minister. The theory is one behavioral mechanism that mediates the mapping from electoral institutions to party-systems -- known as Duverger's Law and Hypothesis. Drawing on data from a cross-section of 39 election surveys conducted under proportional settings, I present individual-level, institutional, and aggregate evidence that support my theory.​

​Why so Few (Large) Parties? A new approach to classifying the number of most effective partiesHow many relatively large parties do elections produce? I suggest to rethink the way we conceptualize large parties as the largest parties that are in close competition, and develop a measures that capture this concept. According to these measures, post-war elections from Western democracies rarely produce more than two large parties. This pattern reoccurs when examining elections under permissive electoral systems, and when examining socially heterogeneous societies. Majoritarian competitions that exist even under proportional settings, particularly over the prime ministership, explain these patterns. Using Cox's (1997) SF-ratio, I exemplify that strategic voting under proportional settings follows similar patterns to strategic voting under majoritarian rules, as implied by the proposed majoritarian competitions that underlie the proportional settings. Moreover, non-proximal voters are largely responsible for the majoritarian patterns found under proportional competitions, supporting my argument.​Portfolios, Expenditures, and Prime Ministers: the Direct Election of Prime Ministers and the Distribution of Payoffs in Israeli CoalitionsGamson's Law -- the proportional allocation of payoffs to coalition members -- is one of the strongest non-trivial empirical regularities political science has produced. However, it contradicts the main prediction from the most cited bargaining model in the discipline -- the party forming the government should receive a disproportionate bonus. I focus on Israeli cabinets, which provide an unusual opportunity to examine the influence the Formateur's bargaining stance has on her coalition payoffs, and alleviate concerns for cross-country differences. I examine two measures: the standard distribution of portfolios, and the allocation of expenditures -- a new measure for policy motivation and office saliency. While both measures follow the expected patterns, findings regarding the distribution of expenditures often lack statistical significance.

Bridging the Gap: How voting behavior informs the analysis of party system fragmentationElectoral institutions and social diversity have long been considered to impact party system fragmentation. However, what social diversity is, and how to measure it, has not been fully developed. Using the standard ethnolinguistic and religious diversity measures, and examining elections from Western democracies, I find very little support for hypotheses that I derive from the party system fragmentation literature. Instead of the standard measures for social diversity, I suggest to test these hypotheses using a host of new measures I derive from the voting behavior literature. I find that diversity of individuals' income, and demographic diversity as measured by combining a large number of variables, both lend much more support to the party system fragmentation hypotheses. Measuring these variables at the electoral district's level, rather than the national level, I also offer more accurate and relevant estimates that are not biased by ecological inference.